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Letters Patent No. 107 ,391, dated September 13, 1870.

SCREW-CLAMP FOR PIANO-PINS.

The Schedule referred to in these Letters Patent and making part of thesame.

To all whom it may concern:

Be it known that I, CHARLES M. LINDSAY, of Forreston, in the county ofOgle and State ot'Illinois, have invented anew and improvedScrew-Fastener for Piano-Pins; and I do hereby declare the following tobe a full, clear, and exact description ofthe same, reference being hadto the accompanying drawing making apart of this specification, inwhichi Figure 1 is plan view;

Figure 2, a side elevation; and

Figure 3, a perspective view.

This invention hns for its object to prevent the pins to which the endsof the strings of pianos or other stringed musical instruments arefastened, and by turning which thc strings are tightened, from turninghackwaldmnder the strain to which they are subject when the strings aretaut.

The invention consists of a stem, having an exterior screw-threadrunning for a little distance from one end, and at the other end afour-sided or polygonal head, in combination with two cross-bars, oneot' which is furnished with a threaded socket of proper size to befitted by the threaded part of the stein, and the other of which hasanoriiice large enough to pass the stem through, this instrument beingintended for use in connection with disks fixed on the heads ofpianopins, and having grooved peripheries, between any two ofA whichdisks the stem, with one ofthe cross-bars on it, is passed, and thenturned into thc socket of the other cross-bar, after which, by applyinga wrench to the head of the stem, the latter may be turned until thecross-bars are drawn as tightlyinto the grooves of the disks as may benecessary, in order to prevent the saine from rotating backward.

In the drawinga is apart of a piano-frame;

l1 are strings of the instrument;

c is the bridge over which the strings pass d are the pins to which theends of the strings. are fastened;

c are the grooved disks fixed on the heads of the pins;

f is thepcylindrical ste-ni; and

71y are the cross-bars.

The sten] and crossbars should be made of hardened steel, and the disksof any softer metal.

Having thus described my invention,

What I claim as new, and desireto secure by Letters Patent, is-

The stem fand cross-bars h, constructed and operating as and for thepurpose described.

- CHARLES M. LINDSAY.

Witnesses JOHN C. GALBRAITH, D. H. REYNOLDS;

